A method for detecting the content of butadiene with different structures in styrene-butadiene resin

Abstract

The invention provides a method for detecting the content of butadiene with different structures in a styrene-butadiene resin. The method comprises the following steps: firstly performing infrared spectrum test on a styrene-butadiene resin film sample to respectively obtain the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene-butadiene resin film sample; then substituting the absorbances of the three types of butadiene structures into formula I, formula II and formula III for calculation, and respectively obtaining the mass percentages of the three types of butadiene structures in the styrene-butadiene resin; the method is a rapid and non-destructive detection method, and also has the advantages of simple analysis steps and cost saving, and the method can also eliminate interference caused by adding a reinforcing agent in the styrene-butadiene resin sample, and can make the detection result have high accuracy.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and particularly relates to a method for detecting the content of butadiene with different structures in butadiene-styrene resin. Background Art

[0002] Butadiene styrene transparent impact-resistant resin, commonly known as K-resin, is a kind of high molecular transparent resin with block structure and / or gradient structure, random structure, linear or star-shaped, which is produced by anionic solution polymerization with styrene and butadiene as monomers and alkyl lithium as initiator. Because K-resin has the characteristics of transparency, high gloss, impact resistance, good flexural resistance, high fluidity, good processing performance, etc., it is widely used in plastic modification (such as PS modification, ABS modification, PC modification and AS modification, etc.), TPR modification, household daily necessities, food packaging and containers, children's toys, cultural supplies, office supplies, medical equipment, transparent displays or transparent shoe materials.

[0003] Generally, the content of styrene in styrene butadiene resin is 70-90%, and the content of butadiene is 10-30%. The proportion of butadiene microstructure is different, which will lead to great differences in performance and different uses. Therefore, the rapid quantitative detection of butadiene microstructure in styrene butadiene resin is conducive to improving the customs clearance speed of styrene butadiene resin at ports and determining HS codes, thereby saving time and avoiding customer losses. At the same time, it is of great significance for the detection of product quality in the market and the protection of consumer rights.

[0004] At present, the commonly used method for analyzing polymers and microstructures and contents is nuclear magnetic resonance. Wang Chao et al. discovered a method for quantitatively analyzing the microstructure of styrene-butadiene rubber. The method firstly qualitatively analyzes the structures of styrene, 1,2-vinyl, cis-1,4-butadiene and trans-1,4-butadiene in SBR by two-dimensional homonuclear and two-dimensional heteronuclear correlation spectra, and then quantitatively analyzes the above four microstructures by nuclear magnetic resonance carbon spectrum. The results show that this method has the advantages of accurate analysis results and simple operation (see "Quantitative Analysis of Microstructure of Styrene-Butadiene Rubber by Nuclear Magnetic Resonance", Wang Chao et al., "Rubber Industry", Issue 10, 2017, pp. 620-623). However, the current method of quantitatively analyzing the microstructure of styrene-butadiene resin by nuclear magnetic resonance has cumbersome operation steps and long detection time, which is not conducive to the rapid detection of samples.

[0005] Therefore, there is an urgent need to develop a simple, rapid and accurate detection method to determine the content of butadiene with different structures in butadiene-styrene resin. Summary of the invention

[0006] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a method for detecting the content of butadiene with different structures in styrene-butadiene resin. The detection method mainly obtains the absorbance of the three structures of butadiene in the styrene-butadiene resin by infrared spectroscopy test, and then substitutes the absorbance of the three structures of butadiene into formula I, formula II and formula III for calculation, so as to directly obtain the mass percentage of the three structures of butadiene in the styrene-butadiene resin. The detection method is simple, efficient and has good accuracy of detection results, and provides a new method for microstructure analysis of styrene-butadiene resin.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for detecting the content of butadiene with different structures in a butadiene-styrene resin, the detection method comprising the following steps:

[0009] (1) Performing infrared spectroscopy test on the styrene butadiene resin film sample to obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene butadiene resin film sample;

[0010] (2) Substituting the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene obtained in step (1) into formulas I, II and III for calculation, the detection results of the content of butadiene with different structures in the styrene-butadiene resin can be obtained;

[0011]

[0012]

[0013]

[0014] In Formula I, Formula II and Formula III, Wt 1,2 Represents the mass percentage of 1,2-butadiene, Wt 顺1,4 Represents the mass percentage of cis-1,4-butadiene, Wt 反1,4 Represents the mass percentage of trans-1,4-butadiene, A 1,2 represents the absorbance of 1,2-butadiene, A 顺1,4 represents the absorbance of cis-1,4-butadiene, A 反1,4 Represents the absorbance of trans-1,4-butadiene.

[0015] The detection method provided by the present invention first uses infrared spectroscopy to test and obtain infrared spectra of three butadiene structures in a butadiene-styrene resin sample. The absorbance of the butadiene of the three structures can be directly read from the ordinate of the infrared spectra (in the infrared spectra, at a wave number of 756 cm -1The corrected peak height corresponding to the left and right readings is the absorbance of the cis-1,4-butadiene structure at a wave number of 909 cm -1 The corresponding corrected peak height for the left and right readings is the absorbance of 1,2-butadiene, and the wave number is 966cm -1 The corrected peak height corresponding to the position is read as the absorbance of trans-1,4-butadiene); secondly, the absorbance of the three different structures of butadiene is substituted into formula I, formula II and formula III for calculation, and the mass percentage of the three structures of butadiene in the butadiene styrene resin sample can be directly calculated. The detection method is a rapid and non-destructive detection method, and also has the advantages of simple analysis steps and saving manpower and material resources. The detection method can eliminate the interference of modified nano-calcium carbonate and carbon black as reinforcing agents on butadiene styrene resin, so that the accuracy of the detection result is very high.

[0016] In order to verify the accuracy of the detection method provided by the present invention, the quantitative detection results obtained by the detection method provided by the present invention can be compared with those obtained by nuclear magnetic resonance ( 1 The quantitative test results obtained by HNMR) test are compared. If the error is within 3.3%, the accuracy of the test method is considered to be high. For the specific NMR test process, please refer to "Quantitative Analysis of Microstructure of Styrene-Butadiene Rubber by Nuclear Magnetic Resonance", Wang Chao et al., Rubber Industry, Issue 10, 2017, pp. 620-623.

[0017] Preferably, the thickness of the styrene-butadiene resin film sample in step (1) is 0.1 to 0.2 mm, for example, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm or 0.19 mm, etc.

[0018] As a preferred technical solution of the present invention, limiting the thickness of the styrene-butadiene resin film sample to 0.1-0.2 mm is conducive to further improving the accuracy of the test results. On the one hand, if the thickness of the styrene-butadiene resin film sample is too low, it will be difficult to observe the characteristic peaks of butadiene and styrene in the infrared spectrum obtained by the test; on the other hand, if the thickness of the styrene-butadiene resin film sample is too thick, the characteristic absorption peaks of butadiene and styrene will be too strong, and may even become flat peaks, which will also make observation very difficult, and then lead to poor accuracy of the test results.

[0019] Preferably, the styrene butadiene resin film sample in step (1) is obtained by laminating the styrene butadiene resin sample in a laminating machine. In the present invention, the styrene butadiene resin sample film is obtained by pressing the styrene butadiene resin in a laminating machine.

[0020] Specifically, the present invention can use a universal film press of Thermo Electric Company, Model P / N 700-0033 when preparing samples; the specific operating steps for preparing samples are as follows: place the film press on a flat table, select different types of spacing rings according to the required film thickness, put the selected spacing ring on the middle column of the base (concave surface facing up, flat surface facing down), then place the aluminum foil on the base in the fixed ring, place the styrene-butadiene resin sample in the center of the aluminum foil, take another piece of aluminum foil and place it on the sample, finally place the upper seat in the fixed ring, place the above-mentioned pressure plate device on the insulating surface, and then heat it. When the pressure plate reaches the target temperature, apply pressure for a period of time, stop heating, and allow it to cool for 3 to 5 minutes while maintaining pressure. After cooling, remove the upper pressure plate, take out the aluminum foil, and carefully peel off the aluminum foil to obtain the styrene-butadiene resin film sample.

[0021] Preferably, the lamination pressure is 20-35 MPa, for example, 22 MPa, 24 MPa, 26 MPa, 28 MPa, 30 MPa, 31 MPa, 32 MPa, 33 MPa or 34 MPa.

[0022] Preferably, the temperature of the lamination is 145-150°C, 145.5°C, 146°C, 146.5°C, 147°C, 147.5°C, 148°C, 148.5°C, 149°C or 149.5°C, etc.

[0023] As a preferred technical solution of the present invention, a lamination temperature of 145 to 150°C is selected to obtain a film of uniform thickness. If the temperature is lower than 145°C, the sample will not be completely dissolved and a thin sheet cannot be made. If the temperature is higher than 150°C, the sample will be cross-linked and yellowed, resulting in impurity contamination.

[0024] Preferably, the film pressing time is 4 to 5 minutes, for example, 4.1 minutes, 4.2 minutes, 4.3 minutes, 4.4 minutes, 4.5 minutes, 4.6 minutes, 4.7 minutes, 4.8 minutes or 4.9 minutes.

[0025] Preferably, the infrared spectrum test includes attenuated total reflection infrared spectrum test or transmission infrared spectrum test, and more preferably transmission infrared spectrum test.

[0026] Attenuated total reflection infrared spectroscopy testing is a method in which infrared radiation penetrates and reflects on the sample surface, interacts with the sample and produces absorption. It has the characteristics and shape of an absorption spectrum and is a non-destructive analysis method. It requires almost no sample preparation for the test product and is easy to operate.

[0027] The attenuated total reflection infrared spectrum test in the present invention uses diamond as the reflective material, so the spectrum is affected by the different absorption of diamond to different bands of infrared light, and it needs to be corrected before analysis to ensure the accuracy of the conclusion.

[0028] As a preferred technical solution of the present invention, since the overall intensity of the reflection spectrum is much smaller than the overall intensity of the transmission spectrum, the transmission infrared spectrum test is preferred.

[0029] Preferably, the infrared spectrum test in step (1) is performed using a Fourier transform infrared spectrometer.

[0030] The present invention can use Fourier infrared spectrometer to perform infrared spectrum test on the sample, deuterated triglycine sulfate potassium bromide (DTGS KBr) detector, with a resolution of 4cm -1 , scanning wave number range 1100~600cm -1 , the scan was accumulated 32 times, the optical path difference (OPD) speed was 0.2cm / S, the infrared light source intensity gain was 1, and the interference of H2O and CO2 was deducted in real time during scanning.

[0031] Preferably, the reflective material used in the attenuated total reflection infrared spectroscopy test is diamond.

[0032] Preferably, the scanning wave number of the infrared spectrum test in step (1) is 1100-600 cm -1 .

[0033] As a preferred technical solution, the detection method comprises the following steps:

[0034] (1) At 145-150° C., a pressure of 20-35 MPa is applied to the styrene-butadiene resin sample by a film press for 4-5 minutes to obtain a styrene-butadiene resin film sample with a thickness of 0.1-0.2 mm;

[0035] (2) Performing an attenuated total reflection infrared spectrum test or a transmission infrared spectrum test on the styrene butadiene resin film sample obtained in step (1) using a Fourier transform infrared spectrometer, with a scanning wave number of 1100 to 600 cm -1 , respectively obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene-butadiene resin film sample;

[0036] (3) Substituting the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene obtained in step (2) into formulas I, II and III for calculation, the detection results of the contents of the three types of butadiene in the styrene-butadiene resin can be obtained;

[0037]

[0038]

[0039]

[0040] In Formula I, Formula II and Formula III, Wt 1,2 Represents the mass percentage of 1,2-butadiene, Wt 顺1,4 Represents the mass percentage of cis-1,4-butadiene, Wt 反1,4 Represents the mass percentage of trans-1,4-butadiene, A 1,2 represents the absorbance of 1,2-butadiene, A 顺1,4 represents the absorbance of cis-1,4-butadiene, A 反1,4 Represents the absorbance of trans-1,4-butadiene.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The method for detecting the content of butadiene with different structures in styrene-butadiene resin provided by the present invention comprises the following steps: firstly, infrared spectroscopy is performed on the styrene-butadiene resin film sample to obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene-butadiene resin film sample respectively; then, the absorbance of the three butadienes obtained is substituted into formula I, formula II and formula III for calculation, and the mass percentage of the three structural butadienes in the styrene-butadiene resin can be obtained respectively. The detection method is a rapid and non-destructive detection method, and also has the advantages of simple analysis steps and saving manpower and material resources, and the detection method can eliminate the interference of modified nano-calcium carbonate and carbon black as reinforcing agents on the styrene-butadiene resin, so that the accuracy of the detection result is very high.

[0043] (2) The error is small when the detection results obtained by the detection method provided by the present invention are compared with the absolute quantitative results obtained by measuring the samples by nuclear magnetic resonance (1HNMR). In addition, the detection sensitivity of the present invention for the change of the microstructure of butadiene is very high and can meet the requirements of analytical accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 1;

[0045] Figure 2 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 2;

[0046] Figure 3 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 3;

[0047] Figure 4 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 4;

[0048] Figure 5 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 5;

[0049] Figure 6 The transmission infrared spectrum of the styrene-butadiene resin obtained by testing in Example 6;

[0050] Figure 7 The attenuated total reflection infrared spectrum of the styrene-butadiene resin obtained by testing in Example 7 is shown in FIG. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0052] Example 1

[0053] A method for detecting the content of butadiene with different structures in a butadiene-styrene resin, the method comprising the following steps:

[0054] (1) At 145°C, a pressure of 30 MPa was applied to the styrene-butadiene resin sample using a film press (Universal Film Maker P / N 0016-010) for 5 min to obtain a styrene-butadiene resin film sample with a thickness of 0.15 mm;

[0055] (2) Using a Fourier transform infrared spectrometer (NICOLET, USA, model NEXUS, OMNI sampler) to perform transmission infrared spectroscopy test on the styrene butadiene resin film sample obtained in step (1), the scanning wave number is 500 to 4000 cm -1 , respectively obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene-butadiene resin film sample;

[0056] (3) Substituting the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene obtained in step (2) into formulas I, II and III for calculation, respectively obtaining the mass percentages of the three structural butadienes in the styrene-butadiene resin;

[0057]

[0058]

[0059]

[0060] In Formula I, Formula II and Formula III, Wt 1,2 Represents the mass percentage of 1,2-butadiene, Wt 顺1,4 Represents the mass percentage of cis-1,4-butadiene, Wt 反1,4Represents the mass percentage of trans-1,4-butadiene, A 1,2 represents the absorbance of 1,2-butadiene, A 顺1,4 represents the absorbance of cis-1,4-butadiene, A 反1,4 Represents the absorbance of trans-1,4-butadiene.

[0061] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.15 mm obtained in this embodiment is as follows: Figure 1 As shown, from Figure 1 The wave number is 756cm -1 The characteristic peaks on the left and right read A 顺1,4 is 0.15309, and the wave number is 909cm -1 The characteristic peaks on the left and right read A 1,2 is 0.04635, and the wave number is 966 cm -1 The characteristic peak reads A 反1,4 is 0.09362, and is substituted into the above formulas Ⅰ, Ⅱ and Ⅲ for calculation to obtain Wt 1,2 11.4%, Wt 顺1,4 49.7% and A 反1,4 It is 38.9%.

[0062] Using nuclear magnetic resonance (NMR) 1 H NMR) was used to measure the styrene-butadiene resin sample provided in this embodiment, and the test results Wt 1,2 ' is 11.3%, Wt 顺1,4 ' is 48.5% and A 反1,4 ' is 39.6%; after comparison, it can be seen that the error is within 3.3%, which shows that the detection result provided by the present invention is very accurate.

[0063] Example 2

[0064] A method for detecting the content of butadiene with different structures in a butadiene-styrene resin, which differs from Example 1 in that 900 ppm of tetramethylethylenediamine is added as a regulator to the butadiene-styrene resin sample provided in Example 1, and the obtained butadiene-styrene resin sample is used as the sample of Example 2, and other parameters and steps are the same as those in Example 1.

[0065] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.15 mm obtained in this embodiment is as follows: Figure 2 As shown, from Figure 2 The wave number is 756cm -1 The characteristic peaks on the left and right read A 顺1,4 is 0.06581, and the wave number is 909 cm -1 The characteristic peaks on the left and right read A 1,2 is 0.09153, and the wave number is 966cm -1The characteristic peak reads A 反1,4 is 0.15763, and is substituted into the above formulas Ⅰ, Ⅱ and Ⅲ for calculation to obtain Wt 1,2 20.5%, Wt 顺1,4 19.5% and A 反1,4 It is 60.0%.

[0066] Example 3

[0067] A method for detecting the content of butadiene with different structures in a butadiene-styrene resin, which differs from Example 1 in that the thickness of the butadiene-styrene resin film sample is 0.1 mm, and other parameters and steps are the same as those in Example 1.

[0068] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.1 mm obtained in this embodiment is as follows: Figure 3 As shown, from Figure 3 The wave number is 756cm -1 The characteristic peaks on the left and right read A 顺1,4 is 0.1682, and the wave number is 909 cm -1 The characteristic peaks on the left and right read A 1,2 is 0.05106, and the wave number is 966cm -1 The characteristic peak reads A 反1,4 is 0.10023, and is substituted into the above formulas Ⅰ, Ⅱ and Ⅲ for calculation to obtain Wt 1,2 11.5%, Wt 顺1,4 50.2% and A 反1,4 It is 38.3%.

[0069] Example 4

[0070] A method for detecting the content of butadiene with different structures in a butadiene-styrene resin, which differs from Example 1 in that the thickness of the butadiene-styrene resin film sample is 0.2 mm, and other parameters and steps are the same as those in Example 1.

[0071] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.2 mm obtained in this embodiment is as follows: Figure 4 As shown, from Figure 4 The wave number is 756cm -1 The characteristic peaks on the left and right read A 顺1,4 is 0.07999, and the wave number is 909cm -1 The characteristic peaks on the left and right read A 1,2 is 0.02479, and the wave number is 966 cm -1 The characteristic peak reads A 反1,4 is 0.04889, and is substituted into the above formulas Ⅰ, Ⅱ and Ⅲ for calculation to obtain Wt 1,2 11.6%, Wt 顺1,449.6% and A 反1,4 It is 38.8%.

[0072] Example 5

[0073] A method for detecting the content of three types of butadiene in a styrene-butadiene resin, which differs from Example 1 in that the thickness of the styrene-butadiene resin film sample is 0.05 mm, and other parameters and steps are the same as those in Example 1.

[0074] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.05 mm obtained in this embodiment is as follows: Figure 5 As shown, from Figure 5 It can be seen that there are many miscellaneous peaks in the infrared spectrum, and the peaks are wide and not on the same baseline, resulting in large errors in the peak height values.

[0075] Example 6

[0076] A method for detecting the content of three types of butadiene in a styrene-butadiene resin, which differs from Example 1 in that the thickness of the styrene-butadiene resin film sample is 0.25 mm, and other parameters and steps are the same as those in Example 1.

[0077] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.25 mm obtained in this embodiment is as follows: Figure 6 As shown, from Figure 6 It can be seen that the characteristic absorption peaks of butadiene and styrene in the infrared spectrum are too strong, resulting in flat peaks and large errors in peak height values, which in turn leads to poor accuracy of the detection results.

[0078] Example 7

[0079] A method for detecting the content of three types of butadiene in a butadiene-styrene resin, which differs from Example 1 in that step (1) performs attenuated total reflection infrared spectroscopy test, diamond is used as the reflective material, and other parameters and steps are the same as those in Example 1.

[0080] The transmission infrared spectrum of the styrene-butadiene resin film sample with a thickness of 0.2 mm obtained in this embodiment is as follows: Figure 7 As shown, from Figure 7 The wave number is 756cm -1 The characteristic peaks on the left and right read A 顺1,4 is 0.03346, and the wave number is 909 cm -1 The characteristic peaks on the left and right read A 1,2 is 0.08551, and the wave number is 966cm -1 The characteristic peak reads A 反1,4 is 0.24724, and is substituted into the above formulas Ⅰ, Ⅱ and Ⅲ for calculation to obtain Wt 1,2 15.6%, Wt顺1,4 8.1% and A 反1,4 It is 76.3%.

[0081] The applicant declares that the present invention illustrates a method for detecting the content of three types of butadiene in a butadiene-styrene resin through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for detecting the content of butadiene with different structures in butadiene-styrene resin, characterized in that: The detection method comprises the following steps: (1) Performing infrared spectroscopy test on the styrene butadiene resin film sample to obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene butadiene resin film sample; (2) Substituting the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene obtained in step (1) into formulas I, II and III for calculation, the detection results of the content of butadiene with different structures in the styrene-butadiene resin can be obtained respectively; In Formula I, Formula II and Formula III, Wt 1,2 Represents the mass percentage of 1,2-butadiene, Wt 顺1,4 Represents the mass percentage of cis-1,4-butadiene, Wt 反1,4 Represents the mass percentage of trans-1,4-butadiene, A 1,2 represents the absorbance of 1,2-butadiene, A 顺1,4 represents the absorbance of cis-1,4-butadiene, A 反1,4 represents the absorbance of trans-1,4-butadiene; The thickness of the styrene-butadiene resin film sample in step (1) is 0.1 to 0.2 mm; In the infrared spectrum test, at a wave number of 756 cm -1 Read the corresponding corrected peak height as the absorbance of the cis-1,4-butadiene structure at a wave number of 909 cm -1 Read the corresponding corrected peak height as the absorbance of 1,2-butadiene at a wave number of 966 cm -1 The corrected peak height corresponding to the position of is read as the absorbance of trans-1,4-butadiene.

2. The detection method according to claim 1, characterized in that: The butadiene-styrene resin film sample in step (1) is obtained by laminating the butadiene-styrene resin sample in a laminating machine.

3. The detection method according to claim 2, characterized in that: The pressure of the film pressing is 20-35 MPa.

4. The detection method according to claim 2, characterized in that: The temperature of the film pressing is 145-150°C.

5. The detection method according to claim 2, characterized in that: The film pressing time is 4 to 5 minutes.

6. The detection method according to claim 1, characterized in that: The infrared spectrum test in step (1) includes attenuated total reflection infrared spectrum test or transmission infrared spectrum test.

7. The detection method according to claim 6, characterized in that: The infrared spectrum test in step (1) is a transmission infrared spectrum test.

8. The detection method according to claim 6, characterized in that: The reflective material used in the attenuated total reflection infrared spectrum test is diamond.

9. The detection method according to claim 1, characterized in that: The infrared spectrum test in step (1) is performed using a Fourier transform infrared spectrometer.

10. The detection method according to claim 1, characterized in that: The scanning wave number of the infrared spectrum test in step (1) is 1100-600cm -1 .

11. The detection method according to claim 1, characterized in that: The detection method comprises the following steps: (1) At 145-150° C., a pressure of 20-35 MPa is applied to the styrene-butadiene resin sample by a film press for 4-5 minutes to obtain a styrene-butadiene resin film sample with a thickness of 0.1-0.2 mm; (2) Performing an attenuated total reflection infrared spectrum test or a transmission infrared spectrum test on the styrene butadiene resin film sample obtained in step (1) using a Fourier transform infrared spectrometer, with a scanning wave number of 1100 to 600 cm -1 , respectively obtain the absorbance of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene in the styrene-butadiene resin film sample; (3) Substituting the absorbances of 1,2-butadiene, cis-1,4-butadiene and trans-1,4-butadiene obtained in step (2) into formulas I, II and III for calculation, the detection results of butadiene with different structures in the butadiene-styrene resin can be obtained; In Formula I, Formula II and Formula III, Wt 1,2 Represents the mass percentage of 1,2-butadiene, Wt 顺1,4 Represents the mass percentage of cis-1,4-butadiene, Wt 反1,4 Represents the mass percentage of trans-1,4-butadiene, A 1,2 represents the absorbance of 1,2-butadiene, A 顺1,4 represents the absorbance of cis-1,4-butadiene, A 反1,4 represents the absorbance of trans-1,4-butadiene; In the infrared spectrum test, at a wave number of 756 cm -1 Read the corresponding corrected peak height as the absorbance of the cis-1,4-butadiene structure at a wave number of 909 cm -1 Read the corresponding corrected peak height as the absorbance of 1,2-butadiene at a wave number of 966 cm -1 The corrected peak height corresponding to the position of is read as the absorbance of trans-1,4-butadiene.

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